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OPM in the News

October 18th, 2017

A team of researchers from Northeastern University in Boston (MA) and the Wenzhou Medical University in China have taken inspiration from cicada wings to develop infection-resistant 3D printed orthopedic implants using PEKK plastic.

With orthopedic implants, there is always the risk that the patient receiving the implant will suffer an infection, caused by having an inorganic device in their body. Typically, antibiotics are used to combat the bacteria causing the infection, though these are becoming less and less effective.

One solution is to keep updating antibiotics to keep up with the bacteria, but one team of researchers saw an opportunity to nip the infections in the bud, so to speak, by creating implants with antibacterial properties.

Consisting of Mian Wang, Garima Bhardwaj, and Thomas J. Webster, the research team was inspired by the cicada—you know, those giant bugs that pop up from the ground to buzz in the summer—whose wings have particular topographical features that help them repel bacteria naturally.

By studying the cicada’s wings, the researchers realized they could mimic its nanostructured surface using 3D printing to create antibacterial implants.

Another important part of the study was the use of PEKK (poly-ether-ketone-ketone) as a material. As the study explains, “A nanostructured surface was fabricated on poly-ether-ketone-ketone (PEKK), a new orthopedic implant chemistry, comprised of nanopillars with random interpillar spacing.”

Live/dead assay of Staphylococcus epidermidis on PEEK and PEKK samples

The 3D printed PEKK samples, which were supplied by Oxford Performance Materials using its OsteoFab technology, were tested in the lab with a number of common bacteria types and, notably, were compared to samples made from PEEK, a standard orthopedic industry material.

After just days, the PEKK samples showed some amazing results. For instance, after five days in the lab, the PEKK sample had 37 per cent less Staphylococcus epidermidis than its PEEK counterpart.

Additionally, the researchers saw a 28 per cent decrease in the amount of Pseudomonas aeruginosa—another bacteria responsible for implant infections—after just one day of culture, and 50 per cent after five days. Amazingly, all these bacterial reductions were achieved without any antibiotics.

“This study demonstrated for the first time, the promise that nanostructured PEKK has for numerous anti-infection orthopedic implant applications,” reads the study’s abstract.

The results of the study show that there is potential to reduce the number of bacterial infections caused by orthopedic implants using 3D printed nanostructures and PEKK material. Considering that infections are on the rise and that they can trigger the need for expensive revision surgeries, the 3D printed solution seems timely.

The entire study, entitled “Antibacterial properties of PEKK for orthopedic applications,” was recently published in the International Journal of Medicine. It can be read in full here.